Heated ultrasonic treating device and treating method for suspended matter-containing liquid

ABSTRACT

A heated ultrasonic treating device ( 6 ) comprising a sump ( 13 ) through which suspended matter-containing liquid passes, a temperature-controllable heater ( 14 ) disposes in the sump ( 13 ), and a ultrasonic vibrator ( 15 ) disposed in the sump ( 13 ). The heated ultrasonic treating device ( 6 ) uses the ultrasonic vibrator ( 15 ) to apply ultrasonic waves while heating organic drain passing the sump ( 13 ) with the heater ( 14 ), thereby pulverizing suspended matters and reducing the amount of SS. In addition, a treating column, where pulverized suspended matter-containing liquid is aerobically treated by aerobic microorganisms, is prevented from efficiency lowering due to clogging.

TECHNICAL FIELD

[0001] The present invention relates to an apparatus and method for heatsonication of a liquid containing suspended solids.

BACKGROUND ART

[0002] Research has conventionally been directed to development ofmethods for treating organic drain water using aerobic microorganisms.In one example of such research and development, kitchen garbagedischarged from houses or the like is crushed using a disposer to beprocessed together with kitchen drain water as drain water containingkitchen garbage.

[0003] The inventor of the present invention previously proposed akitchen garbage processing apparatus performing the followingprocedures. A disposer crushes kitchen garbage discharged from akitchen. A mixture of the crushed kitchen garbage and kitchen drainwater is temporarily collected in a flow-rate adjustment tank. The drainwater supplied from the flow-rate adjustment tank is separated into asolid portion and a liquid portion. The solid portion is processed intocompost using a compost-producing device (solids processor). Afterparticles within the liquid portion are separated through precipitationin a precipitation tank, the remaining supernatant, or organic drainwater, is subjected to aerobic biological treatment (hereinafterreferred to simply as “aerobic treatment”) in treatment columns filledwith a carrier carrying microorganisms (referred to as “microorganismcarrier”), and finally drained.

[0004] However, the organic drain water supplied to the above treatmentcolumn contains fine suspended solids of kitchen garbage, which causefrequent clogging of the microorganism carrier in the treatment column.

DISCLOSURE OF THE INVENTION

[0005] The object of the present invention is to reduce SS (suspendedsolids) in the organic drain water supplied to the treatment column, soas to prevent clogging of the treatment column.

[0006] Specifically, ultrasonic wave is applied to the organic drainwater to be supplied to the treatment column, such that suspended solidsin the organic drain water are micrified and the SS level of the organicdrain water is decreased. A method of processing organic sewage waterwith ultrasonic wave for reducing SS is already known (Japanese PatentLaid-Open Publication No. Hei 11-128975). However, although SS may bereduced, simply applying ultrasonic wave to organic drain water does notsufficiently prevent clogging of the treatment column.

[0007] It is the object of the present invention to provide an apparatusand method for micrifying, using ultrasonic wave, SS (suspended solids)in various liquids containing suspended solids, such as drain watercontaining kitchen garbage, sludge water, and general suspensions.

[0008] According to the present invention, a liquid containing suspendedsolids is subjected to ultrasonic wave while being heated so as tomicrify the suspended solids. In this way, suspended solids in organicdrain water that cannot be sufficiently reduced by simple sonication caneffectively be micrified.

[0009] As a result, the SS level of organic drain water supplied totreatment columns filled with a filler can be minimized, therebypreventing clogging of the treatment column. Accordingly, aerobictreatment of organic drain water can successfully be performed.

[0010] The heat sonication described above is preferably conducted in apool section where the liquid containing suspended solids is temporarilyaccumulated. In this way, effective SS micrification can be performedusing a simple device.

[0011] The organic drain water is preferably drain water obtained byseparating solid materials, using a solid-liquid separator, from thedrain water containing kitchen garbage crushed by a disposer. Theheating temperature is preferably higher than 50° C.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1(a) is a diagram illustrating the general configuration of akitchen garbage processor in which an apparatus and method for heatsonication of sludge according to the present invention are carried out.

[0013]FIG. 1(b) is a diagram showing an apparatus for heat sonication ofsludge according to the present invention.

[0014]FIG. 2(a) is a diagram showing an experimental device for sludgesonication according to the present invention.

[0015]FIG. 2(b) is a graph showing the relationship between SS andprocessing time in an experimental result.

[0016]FIG. 2(c) is a graph showing the relationship between SS andtemperature in an experimental result.

BEST MODE FOR CARRYING OUT THE INVENTION

[0017] An embodiment of an apparatus and method for heat sonication of aliquid containing suspended solids according to the present invention isnext described based on an example by referring to the drawings.

[0018]FIG. 1(a) is a diagram illustrating the configuration of a kitchengarbage processor in which an apparatus and method for heat sonicationof a liquid containing suspended solids according to the presentinvention are carried out.

[0019] The kitchen garbage processor 1 includes a disposer 2, aflow-rate adjustment tank 3, a solid-liquid separator 4, a precipitationtank 5, a heated ultrasonic treating device 6, a treatment column (drainwater processor) 7, and a compost device (solids processor) 8. When thistype of kitchen garbage processor 1 is practiced for a house, thedisposer 2 is installed in an underneath portion of a kitchen sink.Further, the flow-rate adjustment tank 3, the solid-liquid separator 4,the precipitation tank 5, the heated ultrasonic treating device 6, thetreatment column 7, and the compost device 8 are installed outdoorswithin a main body casing (not shown).

[0020] In this kitchen garbage processor 1, aerobic treatment isperformed in the treatment column 7, allowing water to be drained intothe sewer after undergoing adequate purification treatment to avoidnegatively influencing the environment. Furthermore, the compost device8 aerobically processes kitchen garbage to produce fertilizer.

[0021] In the kitchen garbage processor 1, kitchen garbage discardedfrom the sink of a kitchen counter is finely crushed to generate solidmaterials. The solid materials are mixed with kitchen drain water or thelike to form solid-liquid mixture, which is supplied to the flow-rateadjustment tank 3. The solid-liquid mixture including solid sedimentsprecipitated at the bottom of the flow-rate adjustment tank 3 is pumpedby a pump P to be supplied to the solid-liquid separator 4. The flowrate of the solid-liquid mixture supplied to the solid-liquid separator4 is determined by the capacity of the pump P.

[0022] Within the solid-liquid separator 4, the solid-liquid mixture isseparated into solid materials and liquid (organic drain water). Ascreen that separates and eliminates solid materials larger than apredetermined size may favorably be used as the solid-liquid separator4.

[0023] The organic drain water separated as the liquid portion in thesolid-liquid separator 4 is supplied to the precipitation tank 5. In thetank 5, microparticles in the liquid are precipitated, and the remainingsupernatant organic drain water is supplied to the heated ultrasonictreating device 6 by a pump P. At this point, the organic drain watercontains a considerable amount of SS.

[0024] In the heated ultrasonic treating device 6, this organic drainwater is next subjected to ultrasonic wave while being heated, asdescribed later. After SS within the organic drain water are furthermicrified, the organic drain water is supplied to the treatment column7. It is to be noted that SS are solid materials filterable by certainfilter papers, and are reduced through processing by the heatedultrasonic treating device 6.

[0025] The treatment column 7 comprises a filler tank filled with amicroorganism carrier such as sawdust, or wooden chip material.Microorganisms (mainly aerobic bacteria) carried and grown on themicroorganism carrier performs purification treatment of the organicdrain water. The purified organic drain water is discharged to thegeneral sewer. It is to be noted that the inside of the filler tank ismaintained in an aerobic state by allowing air inflow. Preferably, anaerobic state is ensured by forcing air into the tank using a blower orthe like.

[0026] Meanwhile, the solid materials separated within the solid-liquidseparator 4 are supplied to the compost device 8. In the compost device8, aerobic processing is performed on the solid materials bymicroorganisms. It is preferable to maintain, also within the compostdevice 8, a microorganism carrier such as sawdust, or wooden chipmaterial. The inside of the compost device 8 is periodically stirred todisperse the solid materials and to maintain an aerobic state within thetank. In this compost device 8, aerobic microorganisms reproduce, andcompost (organic fertilizer) can be obtained. While carbohydrates arebasically turned into water and carbon dioxide, the solid materials alsoinclude phosphorus, nitrogen, or the like deriving from bones andproteins, which make the obtained compost a good fertilizer includingvarious nutritions.

[0027] Next described are the structure of the heated ultrasonictreating device 6 and its function of micrifying suspended solids. FIG.1(b) is a diagram showing an example structure of the heated ultrasonictreating device 6. The heated ultrasonic treating device 6 includes atubular section. In the present example, the tubular section comprises asubstantially S-shaped tubular trap 10 inside a frame 9. In other words,an inverted U shape is connected to the rear end of an upright U shape,together forming an S shape turned sideways. The incoming end (uppervertical portion) 11 of the tubular trap 10 is connected to theprecipitation tank 5 via a pump P. The outgoing end (lower verticalportion) 12 is connected to the treatment column 7.

[0028] A pool section 13 is formed in the tubular trap 10. Astick-shaped heater 14 is installed protruding into the pool section 13.An ultrasonic oscillator 15 of an ultrasonic oscillating device isprovided at the bottom of the pool section 13. The pool section 13 is aconcavity in which the organic drain water passes through buttemporarily accumulates. The heater 14 is provided to heat the organicdrain water passing through this pool section 13, and is able to adjusttemperature. While the tubular section of the heated ultrasonic treatingdevice 6 according to the present invention is illustrated in thisexample as an S-shaped tubular trap 10, the present invention is notlimited to such a structure. Other structures of the tubular section arepossible, such as a straight tube and a curved tube, as long as theorganic drain water can pass through and be applied with ultrasonic wavewhile being heated.

[0029] Furthermore, the heated ultrasonic treating device 6 need not betubular as long as ultrasonic wave can be applied to the organic drainwater while the water is being heated. In other words, the ultrasonicoscillator 15 and the heater 14 may be arranged within a tank whichtemporarily accumulates the organic drain water. In this case, the tankcorresponds to the pool section 13.

[0030] Provided that the heater 14 can heat the organic drain water, theheater 14 need not be installed in the pool section 13, and may heat thetubular section. Moreover, the ultrasonic oscillator 15 may be installedinside or outside of the tubular section, as long as ultrasonic wave canbe applied to the organic drain water.

[0031] The ultrasonic oscillator 15 is driven by an ultrasonicoscillation main device not shown, and applies ultrasonic wave to theheated organic drain water in the pool section 13. As a result, SS inthe organic drain water are micrified and drastically reduced. Theresulting organic drain water is supplied to the treatment column 7.

[0032] When the heated ultrasonic treating device 6 as described aboveis not provided, suspended solids in the organic drain water deposits onthe microorganism carrier in the treatment column 7 to cause clogging.This degrades water permeability in the treatment column 7, obstructscontact of the organic drain water with the microorganism carrier, andhinders air permeability, thereby remarkably deteriorating the aerobictreatment performed by microorganisms. Specifically, SS in the organicdrain water clog spaces between the microorganism carrier bits togenerate ineffectual spaces, thereby degrading water permeability. As aresult, the organic drain water cannot easily pass through the treatmentcolumn 7. Moreover, determined water paths may become created such thatthe organic drain water ends up passing through without sufficientlycoming in contact with the microorganism carrier.

[0033] According to the present invention, the organic drain watertreated in the treatment column 7 is subjected to ultrasonic wave whilebeing heated in the heated ultrasonic treating device 6. Suspendedsolids in the organic drain water are thereby dispersed and micrified,decreasing the SS level. As a result, clogging of the treatment column 7by suspended solids is much less likely to occur, allowing the organicdrain water to readily contact the microorganism carrier. In addition,air permeability is maintained to improve efficiency of the aerobictreatment by microorganisms.

[0034]FIG. 2 is a diagram describing an experiment for verifying theeffectiveness of the heated ultrasonic treating device 6. FIG. 2(a)shows an experimental device for performing the experiment. In thisexperimental device 16, supernatant 17 of a liquid containing crushedkitchen garbage (supernatant of organic drain water) is provided in acontainer as the raw supernatant for the column experiment. Thissupernatant 17 is pumped by a pump 20 through two tubes 18,19 to besupplied, through one tube, to a heated ultrasonic treating device 6and, through the other, to be sampled as unprocessed control forcomparison.

[0035] In the heated ultrasonic treating device 6, the above-referencedtube is passed through temperature-controlled water, such that thestructure allows temperature of the supernatant to be adjusted andsonication to be performed. In the present experiment, an ultrasonicoscillator 15 of the heated ultrasonic treating device 6 is operated at38 kHZ, 45W to micrify and reduce SS (suspended solids) in thesupernatant. SS of the supernatant 17 is then measured. Meanwhile,temperature of the control is regulated to a constant temperature, forexample. SS of the control is measured without performing sonication.

[0036] FIGS. 2(b) and (c) are graphs indicating results of theexperiment using the above experimental device. The line graph of FIG.2(b) shows the results for the case in which the supernatant is suppliedto the heated ultrasonic treating device 6 and subjected to sonicationwhile being heated to 55° C. The results were obtained by measuring SSof the supernatant discharged from the outlet of the tube 18 afterdifferent lengths of time (processing time) from the point of supplyingthe supernatant. The results are indicated as percentage with respect toSS of the control supernatant which was adjusted to a constanttemperature and discharged from the outlet of the tube 19 withoutperforming sonication (supernatant left at room temperature). Accordingto this experiment, after processing for 3.5 minutes at 55° C., SS levelwas reduced by approximately 30% compared to the control supernatant.

[0037] The dot in the left corner of FIG. 2(b) indicates the measurementresult for the supernatant preheated to 60° C. before micrification inthe heated ultrasonic treating device 6. In this case, more than 50% ofSS was reduced after 4 seconds of processing time (time passed aftersupplying the supernatant). Based on this fact, it is considered thatthe above-referenced time of 3.5 minutes is the time required forincreasing the supernatant temperature, and that suspended solidsinstantly micrify by sonication when preheated.

[0038]FIG. 2(c) shows changes in SS when the supernatant temperature isvaried at a constant processing time of 3.5 minutes. The results areindicated as percentage with respect to SS of the supernatant left at aconstant room temperature without performing sonication. This experimentshows that, at 50° C. or higher, SS level can significantly be reducedcompared to the control.

[0039] As described above, SS level can be decreased by heating andmicrifying the supernatant, although the reason is not clear. However,it is considered that, when the supernatant is heated, lipids includedin SS undergo phase transition to become easily dispersed uponapplication of ultrasonic wave.

[0040] While an embodiment of the present invention has been describedabove based on an example by referring to the drawing, the presentinvention is not limited to such an example. Various embodiments areobviously possible within the scope of the technical features covered bythe claims.

[0041] According to the above-described configuration of the presentinvention, suspended solids in organic drain water that cannotsufficiently be reduced by simple sonication can effectively be treatedby sonication along with heating. As a result, SS level in the organicdrain water to be supplied to the treatment column can be decreased,preventing clogging of the treatment column.

INDUSTRIAL APPLICABILITY

[0042] As the present invention realizes highly efficient micrificationof suspended solids in liquids, the present invention can be used fortreatment of drain water and sludge, and for micrification of otherliquids containing suspended solids.

What is claimed is:
 1. A heated ultrasonic treating device formicrifying a liquid containing suspended solids using ultrasonic wave,comprising: a tubular section through which said liquid containingsuspended solids passes; a temperature-adjustable heater installed insaid tubular section; and an ultrasonic oscillator installed in saidtubular section; wherein while said heater heats said liquid containingsuspended solids passing through said tubular section, said ultrasonicoscillator applies ultrasonic wave to said liquid containing suspendedsolids in said tubular section, thereby micrifying suspended solidsincluded in said liquid containing suspended solids.
 2. A heatedultrasonic treating device for micrifying a liquid containing suspendedsolids using ultrasonic wave, comprising: a pool section through whichsaid liquid containing suspended solids passes; a temperature-adjustableheater installed in said pool section; and an ultrasonic oscillatorinstalled in said pool section; wherein while said heater heats saidliquid containing suspended solids passing through said pool section,said ultrasonic oscillator applies ultrasonic wave to said liquidcontaining suspended solids passing through, thereby micrifyingsuspended solids included in said liquid containing suspended solids. 3.A heated ultrasonic treating device defined in claim 2, wherein saidpool section includes a U-shaped portion, and a bottom part of saidU-shaped portion is used as said pool section.
 4. A heated ultrasonictreating device defined in claim 2, wherein said pool section includesan S-shaped portion, and a bottom part of said S-shaped portion is usedas said pool section.
 5. A heated ultrasonic treating device defined inany one of claims 1 through 4, wherein organic drain water obtainedthrough processing by said heated ultrasonic treating device is suppliedto a treatment column filled with a microorganism carrier for performingaerobic biological treatment therein.
 6. A heated ultrasonic treatingdevice defined in any one of claims 1 through 5, wherein said liquidcontaining suspended solids is drain water obtained through separation,by a solid-liquid separator, of solid materials from drain watercontaining kitchen garbage crushed by a disposer.
 7. A heated ultrasonictreating device defined in any one of claims 1 through 6, wherein saidheater heats said liquid containing suspended solids to or above 50° C.8. A heat sonication method for micrifying a liquid containing suspendedsolids using ultrasonic wave, wherein said liquid containing suspendedsolids is passed through a tubular section, and while a heater heatssaid liquid containing suspended solids inside said tubular section, anultrasonic oscillator applies ultrasonic wave to said liquid containingsuspended solids in said tubular section, thereby micrifying suspendedsolids included in said liquid containing suspended solids.
 9. A heatsonication method for micrifying a liquid containing suspended solidsusing ultrasonic wave, wherein said liquid containing suspended solidsis passed through a pool section, and while a heater heats said liquidcontaining suspended solids inside said pool section, an ultrasonicoscillator applies ultrasonic wave to said liquid containing suspendedsolids in said pool section, thereby micrifying suspended solidsincluded in said liquid containing suspended solids.
 10. A heatedultrasonic treating device defined in claim 10, wherein said poolsection includes a U-shaped portion, and a bottom part of said U-shapedportion is used as said pool section.
 11. A heated ultrasonic treatingdevice defined in claim 10, wherein said pool section includes anS-shaped portion, and a bottom part of said S-shaped portion is used assaid pool section.
 12. A heat sonication method defined in any one ofclaims 9 through 12, wherein organic drain water obtained throughprocessing by said heated ultrasonic treating device is supplied to atreatment column filled with a microorganism carrier for performingaerobic biological treatment therein.
 13. A heat sonication methoddefined in any one of claims 9 through 13, wherein said liquidcontaining suspended solids is drain water obtained through separation,by a solid-liquid separator, of solid materials from drain watercontaining kitchen garbage crushed by a disposer.
 14. A heat sonicationmethod defined in any one of claims 9 through 14, wherein said heaterheats said liquid containing suspended solids to or above 50° C.